EUTECH INSTRUMENTS ALPHA PH 100 PHORP CONTROLLERTRANSMITTER User manual

p
H/OR
MODE
oCSETU READY RELAY
ENTER
7.0
Alpha pH 100 C/CX
pH/ORP
Controller / Transmitter
INSTRUCTION MANUAL
Technology Made Easy ...

1
Preface
This manual serves to explain the use of the Alpha pH
100 pH/ORP Controller/Transmitter. The units covered
are Alpha C and CX pH/ORP Controller/ Transmitter.
The instruction manual functions in two ways: first, as a
step by step guide to help you operate and understand
the operation of the unit and second, as a handy
reference guide.
The information presented in this manual is subject to
change as improvements are made, and does not
represent a commitment of Eutech Instruments Pte Ltd.
This instruction manual is written to cover as many
anticipated applications of the Alpha pH 100 C/CX
pH/ORP Controller/Transmitter as possible. If there are
doubts in the use, please do not hesitate to contact the
nearest Eutech Instruments’ Authorized Distributor or us
at (65) 778-6876.
Eutech Instruments cannot accept any responsibility for
damage or malfunction of the unit due to improper use
of instrument.
Copyright 

1994 Eutech Instruments Pte Ltd.
Version 1.0

2
TABLE OF CONTENTS
1. Introduction------------------------------------------------------------3
2. Getting Acquainted-------------------------------------------------- 4
2.1 Front Panel.............................................................4
2.2 Back Panel.............................................................5
2.3 Selecting pH/ORP Measurement Mode..................6
2.4 Wiring.....................................................................6
3. Operating the Controller-------------------------------------------7
3.1 The Main Display....................................................7
4. Setting Up the Controller ------------------------------------------ 8
4.1 Setting and Changing the Password.......................8
4.1.1 Setting New Password.........................................................8
4.1.2 Changing the Password.......................................................9
5. Calibrating the Controller---------------------------------------- 10
5.1 The Lower Level Menus........................................10
5.2 Calibrating for pH Measurement...........................10
5.2.1 The CAL PH menu.............................................................10
5.3 Changing the Offset..............................................11
5.4 Calibrating for ORP Measurement........................12
5.5 Calibrating for Temperature Measurement ...........12
5.5.1 The CAL °C Menu..............................................................12
5.5.2 ATC ON/OFF.....................................................................13
5.6 Setting the Alarm Feature ...................................15
5.6.1 The Hi SET Menu..............................................................15
5.6.2 The Hi HYS Menu..............................................................16
5.6.3 The Lo SEt Menu...............................................................17
5.6.4 The Lo HYS Menu .............................................................18
6. Using the Controller Current Loop for Datalogging (for
Transmitter Model Only)------------------------------------------------- 19
7. Additional Information-------------------------------------------- 20
8. Appendix 1 - Jumper Positions (Inside Controller)------- 21
9. Appendix 2A - Jumper Positions (pH) ----------------------- 23
10. Appendix 2B - Jumper Positions, ORP --------------------- 24
11. Appendix 3 - pH Offset / Slope-------------------------------- 25
12. Technical Specifications ---------------------------------------- 26

3
1. Introduction
The alpha pH 100 series pH/ORP Controller/Transmitter is the
latest innovation of process controllers from Eutech
Instruments. Incorporated with the ASIC (Application Specific
Integrated Circuit) microprocessor technology, this panel-
mounted on-line controller provides many user-friendly features
desirable in pH/ORP controllers.
This versatile pH/ORP unit can be used either for measuring
and monitoring pH or ORP values at one time. It cannot be
used for measuring both parameters simultaneously. When
shipped, it will be set internally to the pH mode by means of an
internal jumper. This jumper can be reset by you to select
between the pH and ORP mode.
Some of the features of this Controller are :
•Automatic temperature compensation (with PT 100)
•Manual temperature compensation setting without the
temperature probe
•Push button calibration up to 3 points
•Offset adjustment
•High and low alarm triggering relays
•User-defined password feature to prevent unauthorized
entry to change the calibration data, hysteresis function,
high and low setpoints information
•Alarm and operational message annunciators
•Hysteresis function to prevent chattering of relays around
the setpoint
•High-end transmitter model with 4-20 mA current output
for datalogging purposes (pH CTP0100 only)
•Built-in memory backup to ensure that calibration and
other information will not be erased if power supply fails
•Switchable mains voltages of 110 VAC or 220 VAC via
user selectable internal jumper

4
2. Getting Acquainted
2.1 Front Panel
The front panel consists of a 3 digit LED display together with 5
LED annunciators. There are also 4 keys as shown below.
The keys available are the ▲(UP/INCREMENT), ▼
(DOWN/DECREMENT), MODE and ENTER keys.
The annunciators are pH/ORP, °C, SETUP, READY, and
RELAY. The function of the annunciator is to provide additional
information, for example, the pH/ORP annunciator lights up in
pH/ORP measurement mode. The READY annunciator lights
up when the pH/ORP stabilizes. RELAY lights up when any of
the HI SET or LO SET relays is activated.
The MODE key allows you to select between pH or ORP
display, the temperature display or the SETUP menu display.
While in one of the SETUP menus, it also functions as an
ESCAPE key. For example, while setting the Hi SET point, you
can press MODE key if you change your mind about changing
this information.
You can confirm changes or to enter into further levels of the
lower menu by pressing the ENTER key. The ▲
(UP/INCREMENT) and ▼(DOWN/DECREMENT) keys allow
you to change information or to select between different menus.
Holding down the key increases the scrolling speed, i.e.
changeover of 1st digit (ones) to 2nd (tens) and then 3rd digit
(hundreds).
pH/OR
MODE
o
C
S
ET
U
PREAD
Y
RELA
Y
ENTER
8 8 8

5
2.2 Back Panel
The back panel consists of two connectors. The first one is a 4-
way screw terminal and the second is a 12-way screw terminal.
Refer to the label on top of the unit for diagram.
The connection for the 4-way screw terminals are (from the left
to right):
1. PT 100 connection
2. PT 100 connection
3. No connection
4. No connection
The connections for the 12-way screw terminals are (from left
to right),
5. Low Set Relay deactivated position
6. Low Set Relay center pole
7. Low Set Relay activated position
8. High Set Relay deactivated position
9. High Set Relay center pole
10. High Set Relay activated position
11. 4-20 mA - ve connection (for transmitter models only)
12. 4-20 mA + ve connection (for transmitter models only)
13. Protective earth
14. Protective earth
15. Neutral
16. Live

6
2.3 Selecting pH/ORP Measurement Mode
You can set the appropriate pH/ORP measurement mode from
the jumper. See Appendix 1 for details on the jumper positions
for pH mode and Appendix 2 for jumper positions for ORP
mode.
2.4 Wiring
Connect the power supply to the GND (EARTH) - 13 or 14,
NEUTRAL - 15 and LIVE - 16 screw terminals. Make sure that
the power supply jumper setting matches the mains voltage
(110 VAC or 220 VAC). See Appendix 2 for the jumper setting
for the voltage selection.
Connect the pH electrode to the BNC connector at the back
panel. Wire up the PT 100 temperature probe to the PT 100
connections (see back panel connections).
Power on the controller and the display automatically shows the
pH/ORP reading. The pH/ORP annunciator lights up. Once the
reading is stable, the READY annunciator lights up. However, if
the PT 100 temperature probe is not connected, automatic
temperature compensation does not function. You can set the
temperature at a selected value. The temperature is set to
factory default at 25.0 oC.
NOTE : Eutech Instruments will not be responsible for
incorrect application of the controller using improper
voltage sources or wrong jumper settings.

7
3. Operating the Controller
3.1 The Main Display
Press MODE key to switch to three
main displays - the pH/ORP
display, the temperature display
and “SEt” display.
Press MODE key once to get into
the temperature measurement.
The °C annunciator lights up when
you are measuring temperature.
The display shows current
measured temperature (with ATC)
or the temperature that was set in
MTC mode. Press MODE key
again and the display toggles to
the “SEt” for SETUP menu.
Press ENTER key to go into the lower-level setup menus while
the display shows "SEt". These lower-level menus allow
calibration of pH/ORP, Temperature and other parameters
including set password, Hi or Lo Setpoints, and Hi or Lo
Hysteresis values.
pH/ORP
MODE
ENTE
R
7.4
o
C
MODE
ENTE
R
24.0
SETUP
MODE
ENTE
R
SEt

8
4. Setting Up the Controller
4.1 Setting and Changing the Password
4.1.1 Setting New Password
To set a password, press MODE key
until the “SEt” is displayed.
1. Press ENTER key and the
display shows "CAL” and “PH”
alternately. Press ▲key once
and the display shows “SEt”
“id”.
2. Press ENTER to enter your
desired password. Follow the
steps below (e.g. using a
password “123”).
1. Initially, the display shows "000"
with the first digit blinking.
2. Use ▲(UP/INCREMENT) key
to enter “1” on the 1st digit of
the password. Press ENTER
once and the second digit will
blink. Similarly, enter the
second digit of the password “2”
and press ENTER key again.
Repeat with the third digit
accordingly.
3. Press ENTER key and the
display shows “CAL”and ”PH”
alternately. Use ▲or ▼key to
get into the “SEt” and “id”
menu, press ENTER and set your desired password by
following the above steps.
1. Once completed, press ENTER
to confirm and then press
MODE key to return to the pH
display.
SETUP
MODE
ENTE
R
CAL
SETUP
MODE
ENTE
R
PH
SETUP
MODE
ENTE
R
SEt
SETUP
MODE
ENTE
R
id
SETUP
MODE
ENTE
R
123

9
To calibrate the controller at any time, you may have to enter
the password that you set, in order to access the calibration
mode. Once you have entered the password correctly, the
display shows "CAL PH” indicating that you are in one of the
lower-level SETUP menus.
If you enter the wrong password, the display reverts back to the
pH display. Alternatively, if you prefer no password protection,
set the password to “000”, "CAL PH" immediately displays after
you press ENTER key while you are in the "SEt" menu.
NOTE : The user set password is a protection code. Thus, it is
very important to keep this password strictly confidential to
authorized personnel. You are advised to remember the
password that you have set, in order to protect the controller
settings and prevent any unauthorized tampering to the
system!
IMPORTANT : In case the password set is forgotten, use
the master password “555”.
4.1.2 Changing the Password
Enter the Set id menu with already set password or “555”.
Change a new password as per steps mentioned for setting the
password.

10
5. Calibrating the Controller
5.1 The Lower Level Menus
The "CAL PH/CAL OrP" display is the first menu seen upon
entering the lower-level menus, depending on which mode is
set. Press ▲or ▼key to display the various menus as shown
in the figure below. Press ENTER key to go to the lower level
menus.
5.2 Calibrating for pH Measurement
5.2.1 The CAL PH menu
1. Enter this menu by pressing the MODE key twice to the
“SEt” display if you are in measurement mode.
2. Press ENTER key. If the password has been set earlier,
key in the password using the method described in section
4.1. Press ENTER once to confirm. After you set the
correct password, you can see the “CAL” and “PH”
displays, blink alternately.
3. Press ENTER key to enter into the pH calibration mode.
Dip both the pH electrode and temperature probe in the
standard solution for a few minutes.
4. When “CAL PH” displays, press ENTER key. The current
measured value (7 ±0.3 pH) will be displayed. Once the
reading stablizes, press ENTER to confirm.
5. Use ▼keys to scroll to the other buffer values “PH4” and
“PH10”, in that sequence. Press ENTER to confirm and
START
CAL pH /
CAL OrP
CAL oCHi
SEt Hi
Hys Lo
SEt
Lo Hys
SEt id

11
complete the pH calibration, as fo pH 7.0. Press MODE
key to return to measurement mode.
Note : If the pH value is not near
to any buffer, pressing ENTER will
not calibrate the controller. If at
any point, you decide not to
calibrate, you can return to the
previous mode by pressing the
MODE key.
5.3 Changing the Offset
If the controller calibration has
drifted, you can reset the offset of
controller. First, go to the
calibration mode. Press ENTER
when pH7 is being displayed and
the present pH value is shown
(blinking). Using the ▲or ▼key,
change the current pH to 7.0. Press ENTER to confirm, and it
resets the pH calibration curve completely.
NOTE : Gently stir the electrode in a container filled with buffer
solution to create a homogenous sample. Remember to rinse
the electrode before calibrating to the next solution. Minimum
two points calibration is recommended. For full range accuracy,
three points calibration is advised.
This is useful for on-line operations. For example, the
controller while in use shows a reading of pH 8.4. Using a
pre-calibrated portable meter, a measurement is made and
the reading shows pH 8.6. The offset of controller can be set
to 8.6 by going into the CAL mode. While the controller
displays “PH7”, press ENTER. The current reading will be
displayed. Using the ▲or ▼key, change the reading to pH
8.6 to reset the offset. Press ENTER to confirm offset setting.
Press MODE key returns to the controller back to the
measurement mode. This allows a one-point calibration to be
made while the controller is still in operation to adjust for
slight drifts of the controller. For details, prefer to Appendix 3.
SETUP
MODE
ENTE
R
CAL
SETUP
MODE
ENTE
R
PH
SETUP
MODE
ENTE
R
7.0

12
5.4 Calibrating for ORP Measurement
1. Make sure that the ORP mode is
set before calibration.
2. Enter this menu by pressing
MODE key twice to the “SEt”
display if you are in measurement
mode.
3. Press ENTER key. If the password
has been set earlier, key in the
password using the method
described in section 4.1. Press
ENTER once to confirm. After you
set the correct password, you can
see the “CAL” and “OrP” displays
blink alternately.
4. Press ENTER key to enter into the
ORP calibration mode. Dip both
the ORP electrode and temperature probe in the standard
solution for a few minutes.
5. When “CAL OrP” displays, you can see the present mV
value blinking, press ▲or ▼key to adjust the mV value.
To confirm press ENTER key.
6. Press MODE key to return the controller to its
measurement mode.
5.5 Calibrating for Temperature Measurement
5.5.1 The CAL °
°°
°C Menu
1. Enter this menu by pressing MODE
key twice to the “SEt” display if you
are in measurement mode.
1. Press ENTER key. If the password
has been set earlier, key in the
password using the method
described in section 4.1. Press
ENTER once to confirm. After you
set the correct password, you see
SETUP
MODE
ENTE
R
SEt
SETUP
MODE
ENTE
R
CAL
SETUP
MODE
ENTE
R
OrP
SETUP
MODE
ENTE
R
CAL
SETUP
MODE
ENTE
R
oC

13
the “CAL” and “PH” display blinks alternatively. Press ▼
key once, the display shows “CAL”“oC” blinking.
2. Press ENTER and the display alternatively shows “Atc”
and “On” or “Atc” and “OFF”. Use ▲and ▼keys to
choose between both ATC ON and ATC OFF.
5.5.2 ATC ON/OFF
ATC ON : If a PT 100 is connected,
use ▲and ▼keys to adjust the
temperature offset of the PT 100 by
±5 °C. Dip the temperature probe
into the sample liquid. Make sure
that the display is set to ATC ON,
press ENTER and the display now
shows the actual temperature
reading (blinking).
Use ▲and ▼keys to adjust the
reading to its actual temperature -
as measured by an external
thermometer. Once done, press
ENTER key and the display will
flash “CAL” “PH” alternatively.
SETUP
MODE
ENTE
R
A
tc
SETUP
MODE
ENTE
R
On
SETUP
MODE
ENTE
R
23.5

14
ATC OFF : If a PT 100 is not used,
then the ATC should be set to
OFF. In step 3 above, choose by
pressing ▲and ▼keys to select
ATC OFF. Then press ENTER.
The display will now show the
default of 25 oC or the last set
value (blinking). Use ▲and ▼keys
to set your desired value. Press
ENTER to confirm and the display
shows “CAL” “Con”.
Note : For ATC OFF, you can
adjust the set temperature values
from 0.0 to 99.9 oC. This value will
be used for its temperature
compensation e.g. pH in the MTC
mode.
SETUP
MODE
ENTE
R
A
tc
SETUP
MODE
ENTE
R
OFF
SETUP
MODE
ENTE
R
25.0

15
5.6 Setting the Alarm Feature
This menu allows you to change the High and Low Setpoint and
Hysteresis values. See Section 8 for hysteresis applications.
IMPORTANT : When SETUP mode is entered, the 4-20 mA
output (only for transmitter CX model) freezes and the relay de-
activates (if it was in an alarm condition).
5.6.1 The Hi SET Menu
1. Enter this menu by pressing
MODE key twice to the “SEt”
display if you are in
measurement mode.
2. Press ENTER key. If the
password has been set earlier,
key in the password using the
method described in section
4.1. Press ENTER once to
confirm.
3. After you set the correct
password, you see the “CAL”
and “PH” display blinks
alternately. Press ▼key twice,
the display shows “Hi” “SEt”
blinking alternately.
1. Press ENTER key to access the
Hi SET menu and the display
shows the last Hi SET value.
Use ▲and ▼keys to change
the value of the Hi SET point.
2. Press ENTER to confirm the
value of the Hi SET point.
3. Press MODE key to exit to the
measurement mode. You can
press MODE key (as an
ESCAPE key) to revert to the
measurement value if ENTER is
not pressed; the set value is not stored into memory.
SETUP
MODE
ENTE
R
Hi
SETUP
MODE
ENTE
R
8.5
SETUP
MODE
ENTE
R
SEt
T
E : The Hi SEt relay
activates if the current
pH/ORP reading
exceeds Hi SET point
+ ½ Hi HYS value.
The Hi SET value
cannot be lower than
the Low SET value.

16
5.6.2 The Hi HYS Menu
1. Enter this menu by pressing the
MODE key to the “SEt” display
if you are in the measurement
mode.
2. Press ENTER key. If the
password has been set earlier,
key in the password using the
method described in section
4.1. Press ENTER once to
confirm. After you set the
correct password, you see the
“CAL” and “PH” display blinks
alternatively. Press ▼key
thrice, the display shows “Hi”
“HYS” blinking.
1. Press ENTER key to access
the Hi HYS menu and the
display shows the last Hi HYS
value. Use ▲and ▼keys to
change the value of the Hi HYS
point.
2. Press ENTER to confirm the
value of the Hi HYS.
3. Press MODE key to exit to
measurement mode. You can
press MODE key (as an
ESCAPE key) to revert to the
measurement value if ENTER is
not pressed; the set value is not
stored into memory.
SETUP
MODE
ENTE
R
Hi
SETUP
MODE
ENTE
R
0.2
SETUP
MODE
ENTE
R
HYS
NOTE : The
maximum value of
Hysteresis is 0.2 pH
to 2.0 pH or 20 mV to
200 mV. The HI HYS
hysteresis is spread
equally on either side
of the Hi SET point.

17
5.6.3 The Lo SEt Menu
1. Enter this menu by pressing
MODE key twice to the “SEt”
display if you are in
measurement mode.
2. Press ENTER key. If the
password has been set
earlier, key in the password
using the method described in
section 4.1. Press ENTER
once to confirm.
3. After you set the correct
password, you see the “CAL”
and “PH” display blinks
alternately. Press ▼key four
times, the display shows “Lo”
“SEt” blinking alternately.
1. Press ENTER key to access
the Lo SET menu and the
display shows the last Lo SET
value. Use ▲and ▼keys to
change the value of the Lo
SET point.
2. Press ENTER to confirm the
value of the Lo SET point.
3. Press MODE key to exit to
measurement mode. You can
press MODE key (as an
ESCAPE key) to revert to the
measurement value if ENTER
is not pressed; the set value is
not stored into memory.
SETUP
MODE
ENTE
R
Lo
SETUP
MODE
ENTE
R
5.0
SETUP
MODE
ENTE
R
SEt
NOTE : The Lo SEt
relay activates if the
current pH/ORP
reading exceeds Lo
SET point - ½ Lo
HYS value. The Lo
SET value cannot be
higher than the Hi
SET value.

18
5.6.4 The Lo HYS Menu
1. Enter this menu by pressing
the MODE key to the “SEt”
display if you are in the
measurement mode.
2. Press ENTER key. If the
password has been set earlier,
key in the password using the
method described in section
4.1.
3. Press ENTER once to confirm.
After you set the correct
password, you see the “CAL”
and “PH” display blinks
alternatively. Press ▼key five
times, the display shows “Lo”
“HYS” blinking alternately.
1. Press ENTER key to access
the Lo HYS menu and the
display shows the last Lo HYS
value. Use ▲and ▼keys to
change the value of the Lo
HYS point.
2. Press ENTER to confirm the
value of the Lo HYS. Press
MODE key to exit to the
measurement mode. You can
press MODE key (as an
ESCAPE key) to revert to the
measurement value if ENTER
is not pressed; the set value is
not stored into memory.
IMPORTANT : The Lo SET + ½ Lo HYS should be less
than Hi SET - ½ Hi HYS i.e. Hi SET and Lo SET value (in
consideration of the hysteresis band) can never overlap. Lo
HYS and Hi HYS can be set independent of each other; this
allows non-symmetrical hysteresis option.
SETUP
MODE
ENTE
R
Lo
SETUP
MODE
ENTE
R
0.2
SETUP
MODE
ENTE
R
HYS
NOTE : The maximum
value of Hysteresis is
0.2 pH to 2.0 pH or 20
mV to 200 mV. The Lo
HYS hysteresis is
spread equally on
either side of the Lo
SET point.

19
6. Using the Controller Current Loop for
Datalogging (for Transmitter Model Only)
The 4-20 mA Current Loop
A 4-20 mA current loop can be connected if a remote data
logging is required. The current will be proportional to the
pH/ORP displayed on the panel display. The 4-20 mA current
loop can drive a load resistance of no more than 200Ω.
If the pH is less than 0.0 pH, the current signal will be set to
approximately 0 mA. If the pH is greater than 14.0 pH, it will be
set to approximately 21 mA. In this way, the remote data logger
can detect when out of range conditions arise. Please note that
the 4-20 mA loop is not galvanically isolated from the source.